java.lang.AssertionError: assertion failed in Router

[krishnen]

Hi All,

I am using Akka 2.0.1 in my application. I make use of a remote router which i initialize on startup of the application as follows: 

val frameworkAddress = Seq(Address("akka", "FrameworkApplication",

      config.getString("framework.ip-address"),

      config.getInt("framework.akka.remote.netty.port")))

system.actorOf(Props[FrameworkActor].withRouter(

      RemoteRouterConfig(SmallestMailboxRouter(resizer = Some(DefaultResizer(

        lowerBound = 1, upperBound = 10)), routerDispatcher = "framework-dispatcher"),

        frameworkAddress)),

        "framework_server")

The framework-dispatcher is defined in the config is defined as follows : 

framework-dispatcher {

  type = BalancingDispatcher

  executor = "fork-join-executor"

  }

I send a few messages remotely to the router, the first few go through correctly, but at some point the app falls over with this exception:

[ERROR] [05/16/2012 16:32:22.487] [FrameworkApplication-akka.actor.default-dispatcher-5] [akka://FrameworkApplication/user] assertion failed

java.lang.AssertionError: assertion failed

at scala.Predef$.assert(Predef.scala:89)

at akka.routing.Router$$anonfun$receive$1.apply(Routing.scala:309)

at akka.routing.Router$$anonfun$receive$1.apply(Routing.scala:305)

at scala.PartialFunction$$anon$1.apply(PartialFunction.scala:45)

at akka.actor.Actor$class.apply(Actor.scala:311)

at akka.routing.RouterConfig$$anon$1.apply(Routing.scala:176)

at akka.actor.ActorCell.invoke(ActorCell.scala:619)

at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:196)

at akka.dispatch.Mailbox.run(Mailbox.scala:178)

at akka.dispatch.ForkJoinExecutorConfigurator$MailboxExecutionTask.exec(AbstractDispatcher.scala:505)

at akka.jsr166y.ForkJoinTask.doExec(ForkJoinTask.java:259)

at akka.jsr166y.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:974)

at akka.jsr166y.ForkJoinPool.runWorker(ForkJoinPool.java:1478)

at akka.jsr166y.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:104)

I had a quick look at the code, it seems the problem is with router resizing. Can someone point to me what i am doing wrong?

I am running Akka on :

Ubuntu 11.10 

Scala 2.9.1

OpenJDK Runtime Environment (IcedTea7 2.0pre) (7~b147-2.0~pre6-1ubuntu1~ppa1)

OpenJDK 64-Bit Server VM (build 21.0-b17, mixed mode)

If more info needed let me know.

Thanks!

[Jonas Boner]

Sounds like a bug. Do you have a failing test? That would help a lot. Thanks.

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--
Jonas Bonér
CTO
Typesafe - The software stack for applications that scale
Phone: +46 733 777 123
Twitter: @jboner

[√iktor Ҡlang]

Yeah open a ticket. But also, it doesn't make sense at all to have a BalancingDispatcher with a SmallestMailboxRouter...

Cheers,

√

Viktor Klang

Akka Tech Lead

Typesafe - The software stack for applications that scale

Twitter: @viktorklang

[krishnen]

Hello,

I made a small demo project to illustrate the problem :

https://github.com/krishnenc/routing-akka

Viktor : Removing the balancing dispatcher does indeed prevent the exception

Thks,
Krishnen

[√iktor Ҡlang]

On Wed, May 16, 2012 at 7:43 PM, krishnen <kris...@gmail.com> wrote:

Hello,

I made a small demo project to illustrate the problem :

https://github.com/krishnenc/routing-akka

Viktor : Removing the balancing dispatcher does indeed prevent the exception

As I expected then. A remote SmallestMailboxFirst Router, with a Resizer, with a BalancingDispatcher is just a bad idea on all levels.

Great that the assertion was there!

Cheers,

√

 

Thks,
Krishnen

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[Jonas Boner]

On Wed, May 16, 2012 at 7:48 PM, √iktor Ҡlang <viktor...@gmail.com> wrote:
>
>
> On Wed, May 16, 2012 at 7:43 PM, krishnen <kris...@gmail.com> wrote:
>>
>> Hello,
>>
>> I made a small demo project to illustrate the problem :
>>
>> https://github.com/krishnenc/routing-akka
>>
>> Viktor : Removing the balancing dispatcher does indeed prevent the
>> exception
>
>
> As I expected then. A remote SmallestMailboxFirst Router, with a Resizer,
> with a BalancingDispatcher is just a bad idea on all levels.

Indeed bad. But it should not fail like this. Add a ticket.

Jonas Bonér
CTO

Typesafe - The software stack for applications that scale

[√iktor Ҡlang]

How should it fail?

Cheers,
V

[Jonas Boner]

On Wed, May 16, 2012 at 9:02 PM, √iktor Ҡlang <viktor...@gmail.com> wrote:
> How should it fail?
>

With an exception with a proper error message of course.

[√iktor Ҡlang]

That's the easy part, the hard part is where to put that check.

[Jonas Boner]

You'll figure it out ;-)

[√iktor Ҡlang]

On Thu, May 17, 2012 at 1:51 PM, Jonas Boner <jo...@jonasboner.com> wrote:

You'll figure it out ;-)

Nah, looking forward to your pull request since you claimed it was easy. ;-)

[Akka Team]

LOL. I'll take a look.

[√iktor Ҡlang]

On Thu, May 17, 2012 at 2:13 PM, Akka Team <akka.o...@gmail.com> wrote:

LOL. I'll take a look.

We should probably just issue a check for using BalancingDispatcher with a router at all, since it doesn't make any sense really.

[Jonas Boner]

That is the plan

[√iktor Ҡlang]

On Thu, May 17, 2012 at 2:23 PM, Jonas Boner <jo...@jonasboner.com> wrote:

That is the plan

However, that won't help with custom dispatchers.

[Roland Kuhn]

Hi folks,

sorry, I’m very late to the party, but re-reading this I think the change in https://github.com/akka/akka/pull/464 is not needed, since the problem is only that the head router must not run on a “weird” dispatcher. So, Props.dispatcher==BalancingDispatcher is fine for a router while RouterConfig.routerDispatcher==BalancingDispatcher is not. The wording in the docs is less clear than it could be (and I’m accusing myself here, IIRC) and it does not explain which specific combination is bad precisely why.

I’ll open a new ticket to fix the fix.

Regards,

Roland

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Roland Kuhn
Typesafe – The software stack for applications that scale.
twitter: @rolandkuhn

[√iktor Ҡlang]

On Fri, May 25, 2012 at 4:29 PM, Roland Kuhn <goo...@rkuhn.info> wrote:

Hi folks,

sorry, I’m very late to the party, but re-reading this I think the change in https://github.com/akka/akka/pull/464 is not needed, since the problem is only that the head router must not run on a “weird” dispatcher. So, Props.dispatcher==BalancingDispatcher is fine for a router while RouterConfig.routerDispatcher==BalancingDispatcher is not. The wording in the docs is less clear than it could be (and I’m accusing myself here, IIRC) and it does not explain which specific combination is bad precisely why.

I’ll open a new ticket to fix the fix.

Nice catch! Cigar

Cheers,

√

--

Viktor Klang

Akka Tech Lead

Typesafe - The software stack for applications that scale

Twitter: @viktorklang

[Jonas Bonér]

Ah, good catch.

Jonas Bonér
CTO

Typesafe - The software stack for applications that scale

[√iktor Ҡlang]

On Fri, May 25, 2012 at 5:05 PM, Jonas Bonér <jo...@jonasboner.com> wrote:

Ah, good catch.

https://github.com/akka/akka/pull/481